[6.0] Crash after enabling a mixin in example mod

[Lupicus]

After removal of JS coremods, I've trying to get mixin to work in newer versions to replace JS. Mixin works before 60.0.16, but
since then it has issues. I'm hoping it is an easy fix. When running from Eclipse, it fails to launch with this exception not shown in log except
the first line, which is last line in log:

[15:36:22] [main/DEBUG] [cp.mo.mo.TransformationServiceDecorator/MODLAUNCHER]: Initialized transformers for transformation service forge
Exception in thread "main" java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:118)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at net.minecraftforge.bootstrap.Bootstrap.bootstrapMain(Bootstrap.java:133)
at net.minecraftforge.bootstrap.Bootstrap.start(Bootstrap.java:53)
at net.minecraftforge.bootstrap.ForgeBootstrap.main(ForgeBootstrap.java:19)
Caused by: java.lang.module.ResolutionException: Modules MixinExtras and mixinextras.common export package com.llamalad7.mixinextras.lib.apache.commons.tuple to module minecraft
at java.base/java.lang.module.Resolver.resolveFail(Resolver.java:900)
at java.base/java.lang.module.Resolver.failTwoSuppliers(Resolver.java:814)
at java.base/java.lang.module.Resolver.checkExportSuppliers(Resolver.java:735)
at java.base/java.lang.module.Resolver.finish(Resolver.java:380)
at java.base/java.lang.module.Configuration.(Configuration.java:139)
at java.base/java.lang.module.Configuration.resolveAndBind(Configuration.java:493)
at SECURE-BOOTSTRAP/cpw.mods.modlauncher@10.2.4/cpw.mods.modlauncher.ModuleLayerHandler.build(ModuleLayerHandler.java:76)
at SECURE-BOOTSTRAP/cpw.mods.modlauncher@10.2.4/cpw.mods.modlauncher.TransformationServicesHandler.buildTransformingClassLoader(TransformationServicesHandler.java:53)
at SECURE-BOOTSTRAP/cpw.mods.modlauncher@10.2.4/cpw.mods.modlauncher.Launcher.run(Launcher.java:112)
at SECURE-BOOTSTRAP/cpw.mods.modlauncher@10.2.4/cpw.mods.modlauncher.Launcher.main(Launcher.java:75)
at SECURE-BOOTSTRAP/cpw.mods.modlauncher@10.2.4/cpw.mods.modlauncher.BootstrapEntry.main(BootstrapEntry.java:17)
at net.minecraftforge.bootstrap@2.1.7/net.minecraftforge.bootstrap.Bootstrap.moduleMain(Bootstrap.java:188)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
... 4 more

Here is my repo https://github.com/Lupicus/TestMixin/tree/1.21.10-fg6
strangely, it works if using gradlew runClient
strangely, if changed to FG7 it doesn't crash when running from Eclipse, but has other issues.

[LexManos]

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